Patterns in plant community assembly

群落生态学的中心目标是解释自然群落在组成上的巨大差异程度。例如，植物群落在寄主物种的数量、群落资源在常驻物种之间的分配方式以及组成物种的形态上存在差异。虽然已经花了相当大的努力来理解驱动这种变异的机制，但许多问题仍然没有解决，许多相互竞争的理论仍然存在激烈的辩论。例如，很明显，竞争在植物群落中扮演着重要的角色；然而，目前的竞争模型表明，竞争将导致除最具竞争力的物种之外的所有物种被排除在外。鉴于几乎所有的自然群落都包含不止一个物种，顺理成章的是，要么竞争的影响被促进多样性的其他过程(如扩散)缓解，要么竞争过程比我们所知的更复杂，往往不会导致除了最具竞争力的物种之外的所有物种的损失。我和我的学生将通过开发更现实的多物种竞争模型，通过操纵性田间实验测试这些模型，并通过使用零建模技术来识别和量化跨越重要环境梯度的自然群落中竞争、扩散和食草的影响，来检验这些可能性。这项工作将有助于有关这些重要机制如何相互作用以塑造自然社区的越来越多的文献。此外，了解可能增加(例如，扩散)或减少(例如，竞争)多样性的不同机制的相对影响，将极大地为保护和恢复倡议提供信息，并有助于管理入侵物种。

The central goal of community ecology is to explain the substantial degree to which natural communities vary in composition. Plant communities, for example, vary in the number of species they host, how community resources are divided among resident species, and in the morphology of constituent species. While considerable effort has gone into understanding the mechanisms that drive this variation, many questions are still unresolved, and many competing theories are still vigorously debated. For example, it is clear that competition plays an important role in plant communities; however, current models of competition suggest that competition will result in the exclusion of all but the most competitive species. Given that virtually all natural communities contain more than one species, it stands to reason that either the impact of competition is mitigated by other processes that promote diversity, such as dispersal, or that the competitive process is more complicated than we know, and tends not to result in the loss of all but the most competitive species. My students and I will examine these possibilities by developing more realistic models of multi-species competition, testing these models with manipulative field experiments, and by using null modeling techniques to identify and quantify the impacts of competition, dispersal, and herbivory in natural communities spanning important environmental gradients. This work will contribute to the growing body of literature concerning how these important mechanisms interact to shape natural communities. Additionally, understanding the relative impact of different mechanisms that may augment (e.g., dispersal), or reduce diversity (e.g., competition) will greatly inform conservation and restoration initiatives, and aid in the management of invasive species.